New study ensures that smoking cannabis does not alter lung function

By El Planteo

The journal Respiratory Medicine published the latest research from the University of Queensland in Australia. The publication determined that: "There is no consistent association between cannabis use and measures of lung function".

How was the study on marijuana and lung deterioration conducted

To reach this conclusion, they evaluated 1,173 people aged 21 to 30 through two spirometry tests (used to diagnose respiratory disorders), one at the beginning and one at the end of the nine-year period. 

"In this context, it is important to understand more about the harms associated with prolonged marijuana use," explained Jake Najman, the professor responsible for the study, to Forbes.

During the same period, participants were also interviewed to find out if they smoked marijuana, tobacco, both, or none. The data analysis and tests conducted showed that tobacco reduces airflow to the lungs, but cannabis does not; in other words, after nine years of exposure to marijuana smoke, there was no lung disease.

Study conclusions

• - Smoking and co-use of cannabis are risk factors for impaired lung function.

• - At 30 years old, tobacco smokers since adolescence show evidence of impaired lung function.

• - At 30 years old, marijuana smokers since adolescence show no evidence of impaired lung function.

• - The co-use of tobacco and cannabis does not seem to predict lung function, beyond the effects of tobacco use alone.

Other studies contradict these results

On the other hand, a previous study to this one, published by the journal Radiology in November 2022, suggests the opposite. Chest tomographies conducted between 2005 and 2020 on 56 marijuana smokers, 57 non-smokers, and 33 tobacco smokers aged 49 to 60 found that: "Airway inflammation and emphysema were more common in marijuana smokers than in non-smokers and tobacco smokers.

It is worth clarifying that this research did not evaluate people who were only marijuana users. Therefore, the conclusion about inflammation and emphysema is about people who use marijuana and tobacco together.

There are still no certainties, but when comparing the two investigations, a significant difference in the number of patients analyzed (146 from Radiology and 1,173 from Respiratory Medicine) and their age range is noticeable. The participants in the radiology study were much older, their lungs had more years of life and were deteriorating. This simply means that more research is needed to prove the impact of excessive cannabis use.